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Biomedical subjects

C L Christian

Publications and source records attributed to C L Christian.

At least 19 recordsLinked to original sources
PubMed1999

An aggressive form of polyarticular arthritis in a man with CD154 mutation (X-linked hyper-IgM syndrome).

Hyper-IgM syndrome (HIM) is a rare immunodeficiency disorder that has been associated with the development of symptoms and clinical features characteristic of rheumatoid arthritis (RA). We describe a patient with HIM and severe erosive arthritis with prominent nodules in the absence of detectable serum rheumatoid factor. Because HIM results from defects in either T cell CD154 (CD40 ligand) expression or abnormal CD40 signaling, the molecular basis of the patient's disease was analyzed. Activated CD4+ T cells failed to express surface CD154 protein, and molecular analysis of CD154 complementary DNA revealed a nucleotide transversion resulting in the nonconservative amino acid substitution G-D at amino acid 257. This case indicates that defective CD154-dependent CD40 signaling can be associated with susceptibility to a severe inflammatory arthritis that has both similarities to and differences from idiopathic RA.

Adult↗
PubMed1998

Technetium-99m dimercaptosuccinic acid scintigraphy studies of renal cortical scarring and renal length.

UNLABELLED: The aims of this study were to validate 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy appearances with histopathological features of scarring; to evaluate the sensitivity and specificity of 99mTc-DMSA and ultrasound for the detection of renal scarring; to compare planar, pinhole and SPECT techniques when using 99mTc-DMSA; and to compare 99mTc-DMSA and ultrasound renal length measurement. METHODS: Reflux nephropathy was induced in large white pigs using established methods. To ensure that the abnormalities detected were scars and not inflammatory changes, the pigs were not studied until 3 mo after the treated episode of acute pyelonephritis confirmed by 99mTc-DMSA. RESULTS: Twenty pigs were enrolled in the study. Eleven reached the end point, but only nine pigs (18 kidneys) were available for analysis. Thirty-four scars were identified pathologically; 24 were present macroscopically and a further 10 were seen only on microscopy. Technetium-99m-DMSA abnormalities correlated with scars histopathologically with an accuracy of 92% versus that of ultrasound, 75% (p < 0.001). Technetium-99m-DMSA more accurately identified scarring with a higher sensitivity (76% versus 29%) and specificity (98% versus 92%) than ultrasound. On the 99mTc-DMSA study, pinhole imaging had the highest accuracy (92%) when compared with planar (90%) and SPECT (87%) data. These differences were not statistically significant. Renal lengths as measured on 99mTc-DMSA more closely correlated with length measurement at pathological examination than ultrasound. Technetium-99m-DMSA measurement was, on average, 6% higher than pathology, and ultrasound was, on average, 22% lower. CONCLUSION: Technetium-99m-DMSA appears to be the preferred method for the detection of renal cortical scarring and accurate renal length measurement when compared with ultrasound examination.

Animals↗
PubMed1995

An unusual site of heterotopic calcification.

Heterotopic calcification may occur following paralysis from spinal cord injury, most commonly affecting the hips. This case demonstrates a bone scan on a T5 paraplegic patient showing an unusual site of heterotopic calcification in the paravertebral musculature in addition to the hip regions. Subsequent CT scanning confirmed the presence of calcification in the erector spinae musculature.

Aged↗
PubMed1994

Comparison of employees' white blood cell counts in a petrochemical plant by worksite and race.

To determine if employment within a petrochemical plant's quality control (QC) laboratory had any significant effect on the hematopoietic system, and in specific, the white blood cell (WBC) counts, all employees of the QC laboratory were evaluated retrospectively. Trend analysis, linear regression, and Students t tests were performed on all employees of the QC laboratory and on a simple random sample of the rest of this Caribbean petrochemical plant's male employees. Trend analyses revealed a downward trend in 82.6% of the QC laboratory workers and 76.7% in other plant workers. Linear regression and t tests revealed no statistically significant difference by worksite but a significant difference between blacks and whites. The result of the findings of the QC laboratory workers was consistent with that expected in both plant employees and the US general population. A recommendation is made that the Occupational Safety and Health Administration (OSHA) reconsider its WBC cutoff level in the benzene standard.

Adult↗
PubMed1993

Occurrence of antibodies to Borrelia burgdorferi in patients with nonspirochetal subacute bacterial endocarditis.

OBJECTIVE: To determine the prevalence and specificity of antibodies to Borrelia burgdorferi in patients with nonspirochetal subacute bacterial endocarditis and assess whether increased levels of antibodies to B. burgdorferi were attributable to rheumatoid factor. DESIGN: Retrospective case-control study. SETTING: Urban referral center in an area devoid of infected ticks as a source of endocarditis sera. PATIENTS: Sera from 30 consecutive patients with culture-proven subacute endocarditis between 1979 and 1981 were compared with 30 control sera collected between 1989 and 1990. In addition, sera from 20 consecutive patients with rheumatoid arthritis who were positive for rheumatoid factor were collected between 1991 and 1992. Sera were compared with a convenience sample from 15 patients who met the criteria for Lyme disease. MEASUREMENTS: Antibodies to B. burgdorferi were assessed by enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis. IgM rheumatoid factor was quantified using solid-phase radioimmunoassay or latex agglutination techniques. RESULTS: Thirteen of 30 patients with endocarditis (43%) compared with 3 of 30 normal controls (10%) had increased levels of antibodies to B. burgdorferi (P < 0.01). Of these 13 patients, only 1 had an immunoblot consistent with previous infection. The others had nonspecific immunoblots: 5 showed isolated 60-kd reactivity; 1 patient had isolated 41-kd reactivity; and 6 had no bands of reactivity. Immunoblots of the 3 controls with increased antibodies showed only isolated 41-kd reactivity. Thus, the specificity of the B. burgdorferi antibody test in patients with endocarditis was only 60% (95% CI, 42% to 78%), compared with 90% (CI, 79% to 100%) in controls. No correlation was noted between IgM rheumatoid factor and antibodies to B. burgdorferi in patients with endocarditis (r = 0.2; P > 0.2). Only 1 of 20 patients with rheumatoid arthritis without known bacterial infections had antibodies to B. burgdorferi. CONCLUSIONS: Although a positive ELISA test for B. burgdorferi may be a "true positive," a positive serologic test alone does not ensure that the clinical problem is due to Lyme borreliosis. Cross-reactive antibodies to shared epitopes between B. burgdorferi and the endocarditis organism may account for the high false-positive results.

Antibodies, Bacterial↗
PubMed1992

Patients with systemic lupus erythematosus at risk for Pneumocystis carinii pneumonia.

We describe 6 cases of patients with systemic lupus erythematosus (SLE) who developed Pneumocystis carinii pneumonia. All were treated with high dose corticosteroids, and all developed the infection within 4 months of beginning new or revised cytotoxic therapy. All patients tested (5 of 6) were negative for human immunodeficiency virus (HIV). Those patients who developed Pneumocystis carinii pneumonia had more severe lymphocytopenia (median 595 vs 833/mm3) and received higher doses of corticosteroids (median prednisone dose = 43 vs 20 mg/day) than other patients with active SLE. A threshold lymphocyte count of 350/mm3 identified 4 of 6 cases but only 1 of 20 controls. Patients with SLE treated with high dose corticosteroids and cytotoxic drugs and with severe lymphocytopenia may be at increased risk for this opportunistic infection.

Adult↗
PubMed1991

Radiological findings in Hallermann-Streiff syndrome: report of five cases and a review of the literature.

Hallermann-Streiff syndrome (HSS) is a rare disorder with an associated constellation of radiological findings that may aid in the diagnosis of affected individuals. We reviewed the skeletal surveys of 5 affected individuals and noted some characteristic and constant findings. Radiological findings can include a large, poorly ossified skull with decreased ossification in the sutural areas. There was an increase in the number of Wormian bones. Severe mid-facial hypoplasia was present along with a prominent nasal bone. The skull films also showed an abnormally obtuse or nearly straight gonial angle. The teeth appeared small. The long bones were thin and gracile in appearance and often showed poor demarcation of the cortex from the medullary portion. Abnormal bowing of the radius and ulna was seen neonatally in 2 cases. There was widening at the metaphyseal ends of the long bones. The ribs were thin, but normal in length. The vertebral bodies were noted to be small and 3 cases had platyspondyly. There was a decreased number of sternal ossification enters. The metacarpals were also thin and gracile in appearance with metaphyseal widening. We conclude that these characteristic radiological findings in the newborn with HSS can aid in the diagnosis, and a skeletal survey in suspected individuals may be valuable in confirming the diagnosis.

Adolescent↗
PubMed1991

Epidemiology of childhood IDDM in U.S. Virgin Islands from 1979 to 1988. Evidence of an epidemic in early 1980s and variation by degree of racial admixture.

OBJECTIVE: The epidemiology of insulin-dependent diabetes mellitus (IDDM) was evaluated in a predominantly black population in the U.S. Virgin Islands. RESEARCH DESIGN AND METHODS: Primary ascertainment of diabetic subjects was by retrospective review of hospital and clinic records, and IDDM was defined by Diabetes Epidemiology Research International Group criteria. RESULTS: For the period 1979-1988, 28 children less than 15 yr of age were diagnosed with IDDM resulting in an average annual IDDM incidence rate (IR) of 7.5/100,000 (95% confidence interval 4.7-10.3). A significant increase in IDDM incidence (P less than 0.01) was observed when the IR rose to 28.4/100,000 in 1984. White children had the highest IR (28.9/100,000). The IR for Hispanics (7.2/100,000) was slightly higher than that for blacks (5.9/100,000). Among black children, a slight but nonsignificant male excess in incidence was observed (male-female ratio 1.5). When black or Hispanic patients were compared with age-matched control subjects with respect to grandparental race, the diabetic subjects had a greater percentage of white ancestry (P less than 0.02 and P less than 0.05, respectively). The incidence of IDDM in Caribbean blacks (West Indians) in the U.S. Virgin Islands was similar to blacks in the U.S. CONCLUSIONS: The epidemic of IDDM in 1984 provides support for a possible pandemic in the early 1980s.

Adolescent↗
PubMed1991

Development of a registry for diabetes in persons 0-19 years of age in the U.S. Virgin Islands.

A juvenile-onset diabetes registry was recently established in the United States Virgin Islands. Hospital and clinic records were used as the primary sources of case data, while data procured through a physician survey and mass media campaign were used to assess the completeness and validity of the registry listings. The data indicated that 39 people 0-19 years old developed diabetes during the study period (1 January 1979-31 December 1988), of whom 36 probably had Type 1 diabetes. Completeness of the primary source data was estimated at 92.3% and validity seemed very good (around 100%). Evaluation of these registry data has provided new insights into the epidemiology of Type 1 diabetes in the U.S. Virgin Islands.

Adolescent↗
PubMed1990

Prenatal diagnosis of cystic fibrosis.

Since 1983, prenatal diagnosis for CF has been available. The indirect method of microvillar intestinal enzyme analysis was first used, followed by DNA linkage studies by RFLPs, and then aided by disequilibrium data. The past year has brought new promise with the identification of the CF gene and of a single amino acid deletion that is present in 70% of the gene mutations. In the next several years, it is hoped that the remaining mutations will be found, thus increasing the accuracy of prenatal diagnosis by direct detection of the mutations and allowing for carrier testing of the general population.

Chromosomes, Human, Pair 7↗
PubMed1988

Uncommon illness from common infections.

Individual common infectious agents such as EBV, CMV and HBV have well characterized relationships to a variety of acute and chronic disease states; the host and/or environment variables underlying this clinical heterogeneity are not known. Given the high frequency of these viral infections in the general population, there should be a cautious interpretation of antiviral serological data.

Antigens, Viral↗
PubMed1987

Differences among immune complexes: association of C1q in SLE immune complexes with renal disease.

Studies that made use of multiple assay systems demonstrated increased levels of immune complexes (IC) in patients with systemic lupus erythematosus (SLE), but no consistent correlations of IC concentration to patterns or activity of disease have been observed. Furthermore, consistent associations between qualitative differences in IC and disease manifestations have been elusive. IC interaction with erythrocytes and mononuclear phagocytic cells is another variable in SLE that may also mediate some of the biological effects of IC. The present report concerns studies of the composition of purified IC obtained from individuals with SLE and other rheumatic diseases; a 64,000 dalton component identified as the A-B subunit of C1q was detected in purified IC from 27 of 51 SLE patients (53%). The presence of this 64,000 dalton component was not related to either IC concentration or to the serum C1q level. However, the presence of the C1q component in isolated SLE IC did correlate with the presence of renal disease (p less than 0.02). These observations are interpreted relative to a recently described kinetic model of IC clearance.

Antigen-Antibody Complex↗
PubMed1984

Clinical and microbial features of prosthetic joint infection.

A one-year experience with prosthetic joint infection, in which 63 cases were identified, is reviewed. Thirty cases (48 percent) were early infections, in the first postoperative year, and 33 cases (52 percent) were late, occurring more than one year after implantation. Pain was the predominant symptom, but clinical clues suggesting infection were frequently absent, with fever in 43 percent and leukocytosis in only 10 percent. The radiographic appearance was more frequently abnormal in late infections (67 versus 37 percent, p less than 0.02). Staphylococci were predominant organisms, constituting 59 percent of prosthetic joint infections, and S. epidermidis was the predominant species in both early and later infections. Of the hematogenous infections, 11 of 13 occurred in the group with late infections; these were mostly nonstaphylococcal . Antigenic proteins of S. epidermidis were characterized by gel electrophoresis, but no infection-specific antigens could be identified when patient serum was compared with normal samples. Precipitating antibodies to the extracellular proteins of S. epidermidis were present in 50 percent of patients with S. epidermidis prosthetic joint infections, 27 percent of patients with nonstaphylococcal infections, 20 percent of patients with S. aureus infections, and 11 percent of normal subjects. In view of the increasing importance of prosthetic joint infection, further study of the pathogenesis of the infection and the host immune response is warranted.

Adult↗
PubMed1984

Characterization of sequential immune complexes in infective endocarditis by Western blot analysis.

A patient with cutaneous vasculitis during infective endocarditis due to Lactobacillus casei was studied. Immune complexes (IC) were isolated from serum at the time of diagnosis and after 4 wk of therapy. Purification of IC used differential polyethylene glycol precipitation and competitive binding to staphylococcal protein A. In situ radioiodination of IC was performed, followed by SDS-polyacrylamide gel electrophoresis (PAGE). Anti-IC antisera were raised in rabbits by immunization with purified IC. IC were characterized by SDS-PAGE followed by electrophoretic transfer to nitrocellulose, incubation with antiserum and then with 125I protein A, and autoradiography. Although early and late IC differed quantitatively, there were no differentiating immunochemical features. Both IC contained a 60,000 dalton component that did not react with preimmune serum nor with anti-normal human serum. This component reacted with antiserum rendered specific for L. casei by affinity chromatography. The restricted antigen-antibody representation in IC contrasted with a wider panel of antibody activity in patient serum. The Western blot analysis proves to be an ideal method for the characterization of IC because of its sensitivity, dissociative capability, and preservation of immunoreactivity. IC isolated at a time removed from the original antigenic challenge may provide insight into the nature of the inciting antigen.

Animals↗